Overedge sewing machine



Jan. 13, v19448.

N. KNAUS ET AL OVEREDGE SEWING MACHINE Filed Nov. 6, 1945 3, Sheets-Sheet l TNESS ATTORNEY Jax?. 13, 1948. N. KNAUs ETAL l I OVEREDGE SEWING MACHINE 3 Sheets-Sheet 2 Filed Nov. 6, 1945 ATTaRNEY Jan. 13', 1948. N. KNAUs l-:r Aa.

OVEREDGE SEWING MACHINE Filed Nov. 6, 1945 3 Sheets-Sheet 3 INVENToRs QQ/V/C/m/aas Knaus BY Peut/Val c/. Anfon ATTbRNEY Patented Jan. 13, 1948 ovEREDGE SEWING MACHINE Nicholaus Knaus, Cranford, and Percival J. Anton, Elizabeth, N. J., assgnors to The S`nger Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application November 6, 1945, Serial No. 626,936

13 Claims.

This invention relates to sewing machines and more particularly to improved means embodied therein for heinfolding a marginal portion of a workpiece and so presenting it to the trimming and stitch-forming mechanisms that a projecting edge portion of the workpiece is trimmed oir substantially in line with the fold and the hem is secured to the body material by a blind-stitch overedge seam.

A primary object of the invention is to provide an improved guide for the folded portion of the hem-fold.

Another object is so to improve the hem-folder and its edge guide that they will automatically compensate for variati-ons or irregularities in the work such, for example, as by the passage therethrough of a cross seam.

Still another object of the invention is so to mount the hem-folder that vertical movements thereof, due to the passage therethrough of a cross-seam or other locally thickened portion of the workpiece, will shift the folded edge of the workpiece toward the line of needle penetration and thereby insure that the needle will penetrate the folded edge even under adverse conditions which heretofore have frequently resulted in skips.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings,

Fig. l is a front elevation, partly in section, of a portion of an overedge sewing machine showing it tted with one form vof hem-folding attachment particularly adapted for handling tubular work.

Fig. 2 is a plan View thereof.

Fig. 3 is a vertical sectional View taken substantially on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged horizontal sectional view through the hem-folder, taken substantially on the line @-4 of Fig. 1.

Fig. 5 is a view similar to Fig. 4 but showing the folded work within the hem-f older, and showing'in full and in dotted lines the action of a cross-seam on a floating guide-member later to be described.

Fig. 6 is an enlarged vertical sectional View taken substantially on the line 6-6 of Fig. 2..

Fig. 7 is an enlarged vertical sectional view taken substantially on the line l-l of Fig. 2.

Fig. 8 is a diagrammatic view illustrating, more particularly, the location of the pivotal axis of the hem-folder relative to the fold-positioning edge thereof and the relation of said axis and edge to the plane of reciprocation of the needle.

Fig. 9 is a front view of a hem-folding attachment made in accordance with this invention and particularly adapted for handling flat work Fig. 10 is a plan view of the attachment shown in Fig. 9.

Referring more specifically to the drawings, the invention is disclosed as embodied in an overedge sewing machine of the type disclosed in United States patent of N. Knaus, No. 2,238,796, April 15, 1941.

The machine has a main frame I which cary ries a horizontally disposed work-support lb and a throat-plate lc provided with slots through which operates a serrated feed-dog forming a part of a work-feeding mechanism hereinafter referred to. The main frame also supports overedge stitch-forming mechanism comprising a reciprocating curved needle 2, an under or needleloop-taking looper 3 and an overedge looper or loop-spreader 4 which cooperates with the needle 2 and looper 3 in the formation of overedge stitches. The machine also includes a conventional work-feeding mechanism designated generally as f, and a cooperating presser-device for advancing the work to and beyond the stitchforming mechanism. The presser-device comprises a horizontally disposed spring-depressed presser-bar 5 pivoted, at its rear end, to the machine frame and carrying, at its forward end, a presser-foot 6 which overlies the serrated feeddogs which form a part of the work-feeding mechanism. The machine further includes a trimming mechanism which is adapted to trim the work at -one side of the line of seam formation. The trimming mechanism comprises a vibratory trimmer-bar 'l pivotally mounted, at its rear end, on the machine frame and carrying, at its forward end a movable trimmer-blade 8. Vibratory motions are given to the trimmer-bar by an eccentric S, secured upon the rotary main shaft of the machine, through the medium of a link lil having a portion surrounding the eccentric and being connected at Il to a depending part 'laY of the trimmer-bar 1. The link Ill also hasa portion which extends upwardly above the pivotal connection Il and serves as a take-up forthe needle-thread but, as this take-up forms no part of the present invention, the upper part of the link has been broken off.

Cooperating with the upper movable trimmerblade 8 is a lower normally stationary trimmer'- blade I2 mounted in a blade-holder I 3 supported, for horizontal movements, in a pedestal Ia forming a part of the main. frame of the mach-ine. A spring, not shown, mounted in the: pedestal- Ie acts on the blade-holder I3 and constantly urges it toward the right, as seen in Fig. 1, thereby maintaining the blade I2 in pressure contact with the blade 8 to insure trimming of the work.

As hereinbefore indicated, this. invention re lates primarily to improved means, embodied in a: machine of the type above described, for sopresenting the work to the stitch-forming mechannism that the marginal portion of the work is folded into a flattened S-shape with the uppermost portion thereof trimmed substantial-ly in vertical alignment with the lowermost fold. The needle thereupon penetrates the upper ply, adiacent. the trim-medv edge thereof, and passes through the underlying.l fold',l entering and emerging from the same sideI of. the work. The` loopers cooperate. with the needle to forman overedge seam which covers the trimmed edge and secures the hem to the body fabric. by so-ca-lled blind stitching.

When hemming. tubular work the stitching may commence at any point and proceed around the work until the point of beginning has again reached the stitching point. In positioning tu bular work in the machine, preparatory tothe beginning of the hemming operation, itJ is. cus tomary to raisethe presser-foot and to move the work back and forth by' hand, inthe line of seam formation, through the hem-folder and beneath the presser-foot until the work is prop erly' folded and properlyI positioned relative.` to the trimming and stitch-forming mechanisms; after' which the presser-footV is lowered and the sewing begun., For this purpose it is desirable, that the hem-folder be maintained in.A its work ing position.

In. preparing to hem flat work, in which the hemming4 starts at one edge of the work and progresses thereacrossl toI the opposite edge thereof, it is customary to swing the hem-folder upwardly and out of Working position; then to hem-fold the marginal portion of the. work manually and insert it between the presser-foot and the underlying feed-dog, and thereafter to swing the hem-folder downwardly into operative posi tion with the blade of the hem-folder inserted between the lower two plies of the folded hem.

When hemming either tubular or at work, it is desirable that the hem-folder be permitted to have a slight rising and falling movement in its operative position. This movement permits the folder to adapt itself to variations in the thickness of the work such, for example, as when a cross-seam is passing through the folder, and it also permits the folder to rise and fall with the work under the action of the feed-dog.

Referring first to the hem-folder for tubular work shown, in Figs. 1 to 8 inclusive, the device comprises a horizontally disposed support I4, secured to the pedestal Ia by a screw I5, and having, adjacent its free end, a notch I6. Adjustably mounted on the support I4 is a carrier I1 into which is threaded an adjusting screw I8 having a collar I9 entering the notch I6 in the support. Thus, by rotation of the screw I8, the carrier I1 and the parts. carried thereby are moved lengthwise of the support I 4 and transversely of the line of seam formation. The carrier is maintained on the support I4 and slightly frictioned in its movements thereon by a screw 20, passing through a notch 2I in the support I4 and threaded into the carrier I1, and a curved friction washer 22 surrounding the screw and located between, the head thereof and; bearing upon the lower surfaces of both the support and the carrier.

The carrier I 1 is formed with a square, up-

Vstanding block-like portion I1 and a rearwardly off-set portion I1b. The carrier is also provided with two parallel slots 23 and 24, the latter of which formedin the off-set portion I1b. These slots are elongated perpendicularly to the line of seam formation. Slidingly mounted on the upper surface of the. carrier I1 is a floating guide-member G comprising a body portion 25 and front and rear leg portions 25a and 25", respectively, which partially and loosely embrace the raised portion I1a of the carrier I1. The guide-member carries two downwardly projecting pins 26 and 2.1 located, respectively, in the slots 23 and 24 in the carrier. A-coil spring 2'8, having one end located in a horizontal bore 29 in the raised portion I1a of the carrier and its other end seated in a socket 30 in the guide` member G, normally urges the guide-member away from the portion I1a and seats each of the pins 26 and 21 in one end of its respective slot in the carrier, as shown most clearly in Figs. 2 and 4. A screwA 3 I, threaded in the bore 29, backs up the spring 28 and serves as means for' varying the tension of the spring. The edge g of. the guide-member G serves as a guide for the folded portion of the work, as hereinafter will be described. A fixed workguiding member 32 is secured to the side of the carrier I1 by'a dowel pin 33 (Fig. 4) and a screw 34. This. fixed work-guide comprises the rounded outer end 32EL of the member 32 and the overhanging head 35a of a bolt 35 held in the member 32 by a nut 36.

Secured upon the upper surface of the portion I1a of the carrier I1, by a screwl 31, is a saddle 38 having sidev walls. 38 and 38h, affording between them a horizontal rectangular channel 39 (Fig. 7). Pivotally mounted on the saddle 38y byl hinge-member, by a clamp-screw 42 (Fig. 6) isthe shank 43v of a hem-folder 44 which includes the hem-fold gauge wall 45 and the horizontally disposed fold-guiding blade 46. Downward swinging movement of the hinge-member 4I and the hem-folder carried thereby is limited by a stop-screw 41 threaded through the hinge-member and having its lower end resting upon the upper surface of the saddle 38 (Fig. 7). By adjusting the screw 41 the vertical position of the hem-folder may be varied. The screw 41 is maintained in its various positions of adjust ment by the pressure of a relatively soft metal plug 48 slidingly fitted in a bore 49 and urged inwardly into contact with the screw 41 by a thrust screw 50 threaded into the bore 43.

The hinge member 4I and the hem-folder 44 are normally maintained in the position shown in Fig. 1 but, as hereinbefore stated. are permit. ted to have a slight vertical movement. As will be apparent from Figs. 1 and 7', this movement is limited, in a downward direction, by engagement of the screw 41 with the saddle 38 and in an upward direction, by the engagement of the projecting end of a screw threaded into the hinge member 4|, with the overlying surface of an aperture 52 formed in the wall y38a of the saddle.

An important feature of this invention resides in the construction and operation of the oating guide-member G. As above stated, this member is normally urged to the position shown in Fig. 4, by the spring 28. In that position, the edge y thereof lies adjacent the edge 46a of the foldguiding blade 46 and serves as a guide for the folded portion of the work into which the blade 46 extends. Should a thicker piece of work be passed through the device, it will cause the member G to be moved bodily away from the edge 46a, in opposition to the spring 28, but the edge g will continue to bear against the folded edge thereof. As shown most clearly in Fig. 5, the member G is also permitted to have an angular movement in a horizontal plane to permit the passage of a locally thickened portion of the work, such, for example, as a cross-seam. Fig. 5 illustrates a piece of work w, having a hem-fold h and a crossseam s, which, when the work is folded in flattened S-shape, projects beyond the fold t. As shown in full lines in Fig. 5, when the cross-seam s first engages the edge g of the guide-member G it swings that member about the pin 21 (which then acts as a pivot for the member G) in opposition to the spring 28. Movement of the member G in that direction is limited by contact of the leg portion 25a with the side of the raised portion |'|a of the carrier I1. As the work progresses through the device the protruding cross-seam s slides along the guidesurface g thus shifting the member G bodily to the right in opposition to the spring 28 until the seam has reached a point in alignment with the axis of spring 28. When the seam s has passed the axis of the spring 28 it turns the member G clockwise, to the position shown in dotted lines in Fig. 5, thus bringing the pin 26 into engagement with the left end of the slot 23. Engagement of the leg portion 25h with the raised portion of the carrier limits the clockwise movement of the guide-member G. The pin 26 then becomes the pivot for the member G which again is turned counterclockwise, by the pressure of the spring 2B, as the seam s passes rearwardly along the surface g and finally olf the rear end thereof. The guide-member G comes to rest in the position shown in Fig. 4.

From the foregoing, it will be understood that the guide-member G is so constructed and mounted that it is free to be moved bodily and. also to have floating movements in a horizontal plane, thereby to adapt itself to variations in the work while constantly serving as a guide for the work.

In this specification the term floatingf as used in connection with the guide-member G, is intended to mean combined bodily and pivotal movements, as distinguished from the pivotal movement of prior edge guides, such, for example, as that disclosed in United States patent to Washburn, No. 1,941.452, Jan. 2, 1934,

Another important feature of this invention is the location of the pivot 46 of the hinge-member 4| relative to the blade 46 and the plane of reciprocation of the needle This is illustrated most clearly in Fig. 8, from which it will be seen that the pivot 4G is located a distance, indicated as .'12, below a plane y extending horizontally through the blade 43. With this construction and arrangement, upward movement of the blade, such counter-clockwise y as may be caused by a thickened portion of Work passing through the device, causes the edge 46 of the blade to be moved in an arc a thus moving the work, folded about the edge '46e toward the plane n of reciprocation of the needle, there-4 by creating a condition favorable to avoid skipping of stitches.

In prior constructions, the pivot point was located above the plane of the fold-guiding blade and therefore upward movement of the blade caused the work-engaging edge thereof, and the work thereabout, to be moved away from the plane of reciprocation of the needle, with the result that the needle would sometimes fail to pierce the folded edge of the work.

As above stated, in the blind stitch hemming of flat work it is desirable that the hem-folder be capable of being swung upwardly to an inoperative position to facilitate initial positioning of the work. A hem-folder for flat work is disclosed in Figs. 9 and 10. This device differs from the hem folder hereinbefore described only in the construction of the saddle and the parts carried thereby. The other parts are the same as those hereinbefore described and therefore like reference numerals have been applied threto. In this embodiment of the invention a saddle 53 is secured upon the raised portion Ila of the carrier |'l by a screw 54. The saddle 53 is provided with a reduced extension 55 to which is pivoted, by a pin 56, a hinge-member 5l carrying a hemfolder 58 affording a hem-fold gauge wall 59 and a horizontally disposed fold-guiding blade 6B. Aside from its pivotal mounting, this hem-folder is generally similar to the hem-folder 44 described above. One diiference between the hemfolders 44 and 58 is that, in the latter, the blade 66 is materially shorter than the blade 46 of hemfolder 4,4 and terminates short of the toe portion p' of the presser-foot p, as shown at e in Fig. 10. This permits the hem-folder to be swung upwardly to the inoperative position indicated in dotted lines in Fig. 9 to facilitate the placing of the beginning edge of the flat work beneath the presser-foot, as hereinbefore described. The space e, between the blade 60 and the toe p' of the presser-foot, is provided partially by employing a presser-foot having a shorter toe portion than that shown in Fig. 2.

The hem-folder 58vmay be adjusted vertically, in its operative position, by means of a screw 6| threaded into a bore 62 in the saddle 53. The inner end of this screw bears against one end of a thrust pin 63 slidingly mounted in the bore 62 and engaging, at its outer end, an abutment shoulder 64 provided by the hinge member 51.

Having thus set forth the nature of the invention, what we claim herein is:

1. An overedge sewing machine combining overedge stitch-forming mechanism including a reciprocating needle and a cooperating looper, a work-trimming mechanism, a work-feeding mechanism for feeding a workpiece to the trimming and stitch-forming mechanisms. a hemfolder located in advance of said stitch-forming and feeding mechanisms,` and a, horizontally floating guide-member cooperating with the hemfolder to present to said mechanisms a workpiece having a marginal portion thereof folded in S-shape with the lower fold in the line of needle penetration and with the projectingupper,

ply in the line of trimmer operation.

2. An overedge sewing machine combining' overedge stitch-forming mechanism including a, reciprocating needle and a cooperating looper, a

work-trimming mechanism, a work-feeding mechanism for feeding a workpiece to the trimming mechanism, a hem-folder located in ad vance of said stitch-forming and feeding mech anismsand comprising a substantially U-shaped member terminating in a horizontally disposed blade about which the workpiece is folded and a horizontally floating guide-member spring-urged into contact with that portion of the workpiece embracing the edge of said blade, and means to limit the floating movement of the guide-member, said hem-folder serving to present to said mechanisms a workpiece having a marginal portion thereof folded in S-shape with the lower fold in the line of needle penetration.

3. An overedge sewing machine combining a frame, overedge stitch-forming mechanism including a reciprocating thread-carrying needle, a thread-carrying looper and a spreader cooperating with the needle and looper, a worktrimming mechanism, a work-feeding mechanism for feeding a workpiece to the trimming and stitchforming mechanisms, a blind stitch hemming attachment carried by said frame and located in advance of said stitch-forming and feeding mechanisms, said hemming attachment comprising a work folding member which terminates in a horizontally disposed blade about which the workpiece is folded, a fixed edge-guide located forwardly of the folding member, and a horizontally floating guide member located rearwardly of the fixed edge-guide and cooperating with the folding member to present to said mechanisms a workpiece having a marginal portion thereof folded in S-shape with the lower fold in the line of needle penetration and with the projecting upper ply in the line of trimmer operation.

4. An overedge sewing machine combining overedge stitch-forming mechanism including a needle reciprocating in a vertical plane and a cooperating looper, a work-trimming mechanism, a work-feeding mechanism for feeding a workpiece to the trimming and stitch-forming mechanisms, and a pivoted hem-folder located in advance of said stitch-forming and feeding mechanisms with its work-engaging portion at one side of the plane of reciprocation of the needle, the pivot of the hem-folder being so located that initial upward movement of the folder shifts the work-engaging portion thereof toward the plane of reciprocation of the needle.

5. An overedge sewing machine combining a frame, an overedge stitch-forming mechanism including a needle reciprocating in a vertical plane and a cooperating looper, a work-feeding mechanism for feeding a, workpiece to the stitchforming mechanism, a blind stitch hemming attachment located in advance of the stitchforming mechanism and comprising a, support secured to the frame, a hem-folder having a work-engaging portion located at one 'side of the plane of reciprocation of the needle, said hemfolder being pivotally mounted on the support on an axis located at the opposite side of said plane and below the level of said work-engaging portion, whereby initial upward movement of the hem-folder about its pivot moves said workengaging portion toward said plane.

6. A blind stitch hemming attachment for overedge sewing machines comprising a, support, a carrier adjustably secured to said support and provided with a raised portion and a pair of slots, a hem-folder mounted on the carrier, a member slidingly mounted on said carrier and partially surrounding the raised portion thereof and adapted to have a limited horizontal floating movement thereon, said member affording anedge-guide which cooperates with the hem-folder, pins depending from said member and loosely entering said slots, and a spring carried by said raised portion and bearing against said member intermediate said pins and urging the member toward the hem-folder and the pins into engagement with one end, respectively, of the slots.

7. A blind stitch hemming attachment for overedge sewing machines comprising a support, a carrier secured to the support, a hem-folder mounted on the carrier for vertical movement, an edge-guide mounted on the carrier for limited horizontal floating movement, and spring means urging said edge-guide bodily toward the hemfolder.

8. A blind stitch hemming attachment for overedge sewing machines comprising a support, a carrier adjustably secured to the support, a hem-folder, including a folding member affording a work-folding blade pivotally mounted relative to the carrier on an axis located below the level of said blade, an edge-guide mounted on the carrier for limited horizontal floating movement, and spring means urging said edge-guide toward the hem-folder.

9. A blind stitch hemming attachment for overedge sewing machines comprising a support, a carrier adjustably secured to the support, a. saddle secured to said carrier, a hem-folder pivotally mounted on the saddle for vertical movement, means to limit the movement of said hemfolder, an edge-guide mounted on the carrier for limited horizontal oating movement, spring means urging said edge-guide toward the hemfolder, and pin-and-slot connections between said edge-guide and said carrier to limit the floating movement of the edge-guide.

1G. A blind stitch hemming attachment for overedge sewing machines comprising a support, a carrier adjustably secured to the support, a hem-folder mounted on the carrier for vertical movement, a Xed edge-guide carried by said carrier forwardly of said hem-folder, a movable edge-guide mounted on the carrier rearwardly of the fixed edge-guide for limited horizontal floating movement, and spring means urging said floating edge-guide bodily toward the hem-folder.

1l. A blind stitch hemming attachment for overedge sewing machines comprising a support, a carrier secured to the support and having a raised portion, a hem-folder mounted on the carrier for vertical swinging movement, a forked member mounted on the carrier for limited horizontal floating movement and partially surrounding said raised portion, said member affording an edge-guide which cooperates with said hemfolder, and spring means urging said edge-guide toward the hem-folder.

12. A blind stitch hemming attachment foi over-edge sewing machines comprising a support, a

carrier adjustably secured to the support and' 9 10 being complemental to said work-support in fold- REFERENCES CITED ing the Work, a fold-edge guide opposed to said edge of said blade, and supporting means providlhf ftgvgrgerens are of record m the ing for both pivotal and bodily yielding movements of said guide relatively to said blade. 5 UNITED STATES PATENTS NICHOLAUS KNAUS- Number Name Date PERCIVAL J. ANTON. 1,941,452 Washburn Jan. 2, 1934 

